* {
    margin: 0;
    padding: 0;
}

.w {
    margin: 0 auto;
    width: 1200px;
}

.clearfix::after {
    content: '';
    display: block;
    height: 0;
    clear: both;
    visibility: hidden;
}

body {
    background-color: #f3f5f7;
}

.header {
    height: 43px;
    margin: 30px auto;
}

.logo {
    float: left;
    width: 198px;
    height: 42px;
}

li {
    list-style: none;
}

.nav li {
    float: left;
    margin: 0 15px;
}

.nav li a {
    text-decoration: none;
    display: block;
    color: #050505;
    font-size: 18px;
    padding: 0 10px;
    height: 42px;
    line-height: 42px;
}

.nav li a:hover {
    border-bottom: 2px solid #00a4af;
    color: #00a4af;
}

.nav {
    float: left;
    margin-left: 60px;
}

.search {
    float: left;
    width: 412px;
    height: 42px;
    margin-left: 50px;
}

.search input {
    float: left;
    width: 360px;
    height: 40px;
    border: 2px solid #00a4af;
    border-right: 0px;
}

.search .btn {
    /* 因为 input和 button属于行内块元素 中间会有缝隙 ，所以需要添加浮动 让他们紧贴 */
    float: left;
    width: 50px;
    height: 44px;
    background-image: url(../image/btn.png);
    border: 0;
}

.user {
    float: right;
    margin-left: 40px;
    font-size: 14px;
}

.user img {
    display: inline-block;
    height: 42px;
    line-height: 42px;
    vertical-align: middle;
}

.banner {
    height: 421px;
    background-color: blue;
}

.banner .w {
    margin: 0 auto;
    height: 421px;
    background-color: pink;
    background: url(../image/banner2_20190819_210028.png) no-repeat scroll top;
}

.banner .w .subnav {
    float: left;
    width: 190px;
    height: 421px;
    background-color: rgba(0, 0, 0, 0.3);
}

.subnav li {
    width: 160px;
    height: 47px;
    margin: 0;
    padding: 0 20px;
    line-height: 47px;
}

.subnav li a {
    font-size: 14px;
    color: #fff;
}

.subnav ul li a span {
    /* position: absolute; */
    float: right;
    /* right: 10px; */
}

.subnav ul li a:hover {
    color: #00a4af;
}


/*课程模块*/

.course {
    float: right;
    width: 230px;
    height: 300px;
    background-color: #fff;
    /* 浮动的盒子不会有外边距合并的问题 */
    margin-top: 50px;
}

.course h2 {
    height: 48px;
    background-color: #9bceea;
    text-align: center;
    line-height: 48px;
    font-size: 18px;
    color: #fff;
}

.bd {
    padding: 0 20px;
}

.bd ul li {
    padding: 14px 0;
    border-bottom: 1px solid #ccc;
}

.bd ul li h4 {
    font-size: 16px;
    color: #4e4e4e;
}

.bd ul li p {
    font-size: 12px;
    color: #a5a5a5;
}

.bd .more {
    display: block;
    height: 38px;
    border: 1px solid #00a4ff;
    margin-top: 5px;
    text-align: center;
    line-height: 38px;
    color: #00a4ff;
    font-size: 16px;
    font-weight: 700;
}


/*精品模块*/

.god {
    height: 60px;
    background-color: #fff;
    box-shadow: 0 2px 3px 3px rgba(0, 0, 0, .1);
}

.god h3 {
    float: left;
    width: 80px;
    color: #00a4ff;
    line-height: 60px;
    padding: 0 35px;
}

.god ul {
    float: left;
}

.god ul li {
    float: left;
}

.god ul a {
    text-decoration: none;
    font-size: 16px;
    padding: 0 30px;
    line-height: 60px;
    border-left: 1px solid #000;
}

.god h4 {
    float: right;
    width: 80px;
    color: #00a4ff;
    line-height: 60px;
    padding: 0 35px;
}

.box {
    margin-top: 30px;
}

.box-hd {
    height: 45px;
}

.box-hd h3 {
    float: left;
    font-size: 20px;
    font-weight: 400;
}

a {
    text-decoration: none;
}

.box-hd a {
    float: right;
    color: #a5a5a5;
    margin: 10px 30px;
}


/* 图片模块 */

.box-bd ul {
    /*如果以后父盒子不够撑开盒子 那就给父盒子增大宽度*/
    width: 1225px;
}

.box-bd ul li {
    position: relative;
    width: 230px;
    height: 270px;
    float: left;
    margin-right: 15px;
    margin-top: 15px;
}

.box-bd ul li img {
    width: 100%;
}

.box-bd ul li .hot {
    position: absolute;
    width: 40px;
    right: -4px;
    top: 0px;
}

.box-bd ul li h4 {
    font-size: 16px;
    padding: 20px 20px;
    font-weight: 400;
}

.box-bd ul li .info {
    font-size: 14px;
    color: #999;
    margin: 0 30px;
}

.box-bd ul li .info span {
    color: orange;
    margin-right: 20px;
}


/* 尾部模块 */

.footer {
    height: 415px;
    overflow: hidden;
}

.footer .w {
    margin-top: 32px;
}

.footer .copyright {
    float: left;
}

.footer .copyright p {
    font-size: 12px;
    margin: 10px 0;
    color: #666;
}

.footer .copyright a {
    display: block;
    height: 33px;
    width: 120px;
    border: 1px solid #00a4af;
    font-size: 16px;
    text-align: center;
    line-height: 33px;
    color: #00a4ff;
}

.footer .links {
    float: right;
}

.links dl {
    float: left;
    margin-left: 100px;
}

.links dl dt {
    font-size: 16px;
    color: #333;
    margin-bottom: 30px;
}

.links a {
    color: #333;
}